1. Field of the Invention
The inventive device relates to special kinds of umbrella that can cope with strong wind.
2. Description of the Related Art
It is known that there has been a kind of umbrella which is designed to allow its cover to be inverted upward when a strong wind acts thereon and the umbrella is restored to its normally closed condition by simply pulling the runner downwardly along the shaft.
This kind of umbrella is sold under the trademark "WINDFLEX umbrella" in the market place.
There is another kind of umbrella which is designed to prevent its cover from being inverted even when a strong wind acts thereon. Such umbrella is generally sold under the trademark "WINDLOCK umbrella".
The schematic representation of the aforesaid WINDFLEX umbrella and WINDLOCK umbrella are exhibited in FIG. 1 and FIG. 2, respectively.
One shortcoming of the WINDFLEX umbrella is that its cover is easily inverted, whereas in the WINDLOCK umbrella a strong friction occurs, as shown in FIG. 2, along the contacting faces between its holder cords (D-E) and stretchers (B-C) when opening and closing the umbrella, due to the arrangement of all points A, B, C and E being on the same plane.